COLORADO SPRINGS, Colo. — A gunman killed one person and wounded four others before being shot dead by a security guard at a busy Colorado Springs megachurch on Sunday, authorities said.

The shooter, who was not identified, was shot dead in the parking lot by a church security guard, Colorado Springs police chief Richard Myers said at a news conference.

The attack started when a gunman in a black trench coat and a high-powered rifle entered the church's main foyer about 1 p.m. and began shooting, according to a source who was locked down at the church Sunday afternoon, who spoke to The Associated Press on condition of anonymity because the police department had asked that it release all information.

The church's 11 a.m. service had recently ended, and hundreds of people were milling about when the gunman opened fire. Nearby were parents picking up their children from the nursery.

Police arrived to find that the gunman had been killed by a member of the church's armed security staff, Myers said.

"There was a courageous staff member who probably saved many lives here today," Myers said.

Gov. Bill Ritter ordered state authorities to help investigate. The FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives were assisting, and officers combed the church campus looking for suspicious devices.

At least three people were taken to Penrose Community Hospital in Colorado Springs, where they were listed in critical, fair and good condition, hospital spokeswoman Amy Sufak said.

Rampage related to earlier shooting?It was not immediately known if the attack was related to an earlier shooting in a Christian mission training program in Arvada, a town about 70 miles away.

The mission training program has a small office at the church's World Prayer Center on the New Life campus.

Arvada authorities said they were sharing information with Colorado Springs investigators.

New Life was founded by the Rev. Ted Haggard, who was fired last year after a former male prostitute alleged he had a three-year cash-for-sex relationship with him. Haggard, then the president of the National Association of Evangelicals, admitted committing undisclosed "sexual immorality."

The New Life Church is one of Colorado's largest, with about 10,000 members.